During the last twenty years, our knowledge regarding the general mechanism involved in the synthesis of protein from information encoded in the polydeoxynucleotide sequences in DNA has improved greatly. The control of protein synthesis is less well understood and the evolution of a recognition code, whereby a protein molecule of defined sequence can recognize and bind to a specific sequence of a DNA molecule, is a subject of intensive investigation. In recent times, it has become possible to characterize and synthesize the operator segment of the lac-operator gene, which provides for an essentially negative control mechanism in the metabolism of lactose by the bacterium E. coli. This proposal is concerned with the application of UV, IR, Fluorescence, and relaxation kinetic methods to synthetically prepared oligonucleotide sequences as found in the lac-operator gene in order to obtain mechanistic details regarding the recognition code. This would involve thermodynamic and temperature jump relaxation studies on relevant oligonucleotides to understand the dynamics of base recognition and helix coil transitions. Similarly, experiments are proposed to investigate the detailed mechanism of lac-operator-repressor protein interaction, as well as the binding of metal ions (mg2 ion, Ca2 ion, Li ion, Na ion) to oligonucleotides. Studies on the binding of pertinent amino acids and oligopeptides to different sizes of the lac-operator gene will be undertaken.